September 11, 2001, started off as a clear, beautiful late summer day on the East Coast of the United States. New Yorkers were preparing to vote in a mayoral primary, businessmen and women and tourists in New York and Washington, D.C., were going about their regular lives, children had just started back recently in school from the long summer break, and, despite terrorist attacks against U.S. targets both at home (the World Trade Center in 1993) and abroad (the Cole attack and the Tanzania and Kenya embassy bombings), Americans felt secure. That was all about to change, and the change wrought that day has affected the lives of Americans every day for the past 10 years.

Photograph from a security camera at the Portland, Maine, airport showing lead hijacker Mohammed Atta passing through a security checkpoint at 5:53 am on the morning of September 11, 2001. Credit: United States District Court for the Eastern District of Virginia (U.S. v. Moussaoui).

What ended in terror in New York, the Pentagon outside Washington, D.C., and a field near Shanksville, Pennsylvania, and shook the world began in Maine. Over the next 10 days, we’ll take a pictorial retrospective look at the 9/11 attacks and their aftermath. Today, we begin with this security camera still from the airport in Portland, Maine. The timestamp reads 5:53:41 AM, and it shows lead hijacker Mohammed Atta passing through the security checkpoint. Less than three hours later, at 8:46 AM in New York City, the first plane would strike the World Trade Center‘s north tower.

The pictures over the next 10 days and in our Britannica’s fuller pictorial retrospective shows not only the devastation and the terror of the day but also the perseverance and the courage that followed.